Known types of on-board fuel vapor management systems comprise a vapor collection canister that collects and stores fuel vapor emitted from a tank containing volatile liquid fuel for the engine. A canister purge solenoid (CPS) valve periodically purges collected vapor to an intake manifold of the engine where it entrains with induction air or with an induction air-fuel charge for combustion in the engine combustion chamber space. One type of CPS valve comprises a solenoid that is under the control of a microprocessor-based engine management system. Because vapor storage systems such as carbon canisters have a finite capacity to adsorb fuel vapor, fuel vapor may be periodically emitted into the atmosphere when vapor storage systems exceed adsorption capacity.
One problem with the current designs of carbon canisters is that they require a complicated support structure to maintain the carbon bed integrity. Further, they require additional components, such as a dust/filter separator, vent valves, and vapor lines that incrementally add to the cost and complexity of the fuel vapor management systems.
It is thus desirable to provide a system that eliminates the need for carbon canisters and its related components while preventing the exposure of hydrocarbons to the atmosphere.